fix: cr suggestions

Author: nrwiersma

examples/w5500/main.go

@@ -16,10 +16,8 @@ func main() {
 	})
 	machine.GPIO17.Configure(machine.PinConfig{Mode: machine.PinOutput})
 
-	eth := w5500.New()
+	eth := w5500.New(machine.SPI0, machine.GPIO17.Set)
 	eth.Configure(w5500.Config{
-		SPI:        machine.SPI0,
-		CS:         machine.GPIO17.Set,
 		MAC:        net.HardwareAddr{0xee, 0xbe, 0xe9, 0xa9, 0xb6, 0x4f},
 		IP:         netip.AddrFrom4([4]byte{192, 168, 1, 2}),
 		SubnetMask: netip.AddrFrom4([4]byte{255, 255, 255, 0}),

w5500/io.go

@@ -104,13 +104,13 @@ func (d *Device) sendReadHeader(addr uint16, bsb uint8) {
 	buf[0] = byte(addr >> 8)
 	buf[1] = byte(addr & 0xff)
 	buf[2] = bsb<<3 | 0b000
-	_ = d.bus.Tx(buf, nil)
+	_ = d.bus.Tx(buf[:], nil)
 }
 
 func (d *Device) sendWriteHeader(addr uint16, bsb uint8) {
 	buf := d.cmdBuf
 	buf[0] = byte(addr >> 8)
 	buf[1] = byte(addr & 0xff)
 	buf[2] = bsb<<3 | 0b100
-	_ = d.bus.Tx(buf, nil)
+	_ = d.bus.Tx(buf[:], nil)
 }

w5500/w5500.go

@@ -33,22 +33,21 @@ type Device struct {
 	sockets []*socket
 	laddr   netip.Addr
 
-	cmdBuf []byte
+	cmdBuf [3]byte
 }
 
 // New returns a new w5500 driver.
-func New() *Device {
+func New(bus drivers.SPI, cs PinOutput) *Device {
 	return &Device{
-		cmdBuf: make([]byte, 3),
+		bus: bus,
+		cs:  cs,
 	}
 }
 
 // Config is the configuration for the device.
 //
 // The SPI bus must be fully configured.
 type Config struct {
-	SPI drivers.SPI
-	CS  PinOutput
 	DNS Resolver
 
 	MAC        net.HardwareAddr
@@ -64,13 +63,11 @@ type Config struct {
 //
 // MAC address must be provided. The other fields are optional.
 func (d *Device) Configure(cfg Config) error {
-	cfg.CS(true)
+	d.cs(true)
 
 	d.mu.Lock()
 	defer d.mu.Unlock()
 
-	d.bus = cfg.SPI
-	d.cs = cfg.CS
 	d.dns = cfg.DNS
 
 	d.reset()